1. Field of the Invention
The present invention relates to a twin-axle rail vehicle bogie.
2. Description of the Related Art
Conventional bogies are known which are provided with a bogie frame comprising a cross beam extending transversely to the direction of travel and longitudinal beams being attached to the cross beam and extending in the direction of travel. Conventionally, the cross beam supports a centrally arranged pivoted bolster serving to connect the bogie to the bottom side of the vehicle so that it is pivotal about the vertical axis. The two wheel sets are externally hingedly connected to a main suspension system with a substantially vertically directed spring force. Conventionally, the upper, free end of the suspension system is hingedly connected to the longitudinal beam. Furthermore, the wheel set is hingedly connected to the bogie frame by longitudinal control arms for the transfer of longitudinal forces. In order to achieve a suitable rigidity of the bogie frame, conventional longitudinal beams used to be linked with each other on their outer free ends by additional cross beams, so that in fact a closed frame was used.
For certain special vehicles, however, it was desirable to make the bogies light, as compact as possible and of particularly small overall height. For these purposes, it was desirable to use wheels of smaller diameter, which, however, led to problems with regard to derailment safety. Therefore, a considerable static spring deflection height of the wheel set in connection with a hydraulic oscillation damper system had to be provided. As a consequence, the vertically extending main suspension system had to be made accordingly large, resulting in an undesirably great overall height. Apart from that, the conventional bogie frame with longitudinal beams was relatively heavy and of great overall height, which is also due to the fact that the longitudinal beams of the conventional bogie frame were required to extend in a position above the wheel in order to accommodate the springs.
The DE-AS 24 44 887 discloses a bogie for rail vehicles which is included in the generic category, with a link being hingedly connected to a bogie cross beam at one of its free ends and supporting the wheel set bearing on its other free end. Suspension is effected by leaf springs entending below the link.